The invention relates to a method for video signal processing.
It is a complex task to implement video signal processing algorithms in hardware. Such hardware is typically referred to as video processing core. During the design process of a video processing core evaluation and verification are very important steps. Developing a video processing core, i.e. a core processing module for a single video format, e.g. PAL format or NTSC format, represents the lowest requirement and thus a fast and controllable design effort. Maintaining this single format design environment is desirable. It has to be noted that the format names “PAL” and “NTSC” throughout this description only denote the number of pixels per video line, the number of video lines per field and the field rate common to these formats as specified in the digital video format ITU-R 656. The names originate from the analogue format specifications and specify more parameters, such as colour coding, modulation schemes, and so on. But throughout this description only the mentioned parameters pixels per line, lines per field and fields per second will be referenced.
In other words, it is desirable to be able to use a video processing core designed for a specific video format for other video formats as well.
For this purpose, in prior art, a video signal of an input format that is different from the processing format of the processing core, i.e. the format the processing core is designed for, is completely converted into a video signal having said processing format. However, such a complete conversion has several disadvantages, e.g. the longer time needed for format conversion, additional needed hardware, as well as a differing temporal base for fields which influences motion rendering. Also, large memories and logic functions are needed to perform a full format conversion process.